FIG. 1 illustrates a conventional optical network. The network includes a plurality of interconnected optical rings 101-103. Each ring includes a plurality of nodes 104, also known as shelves. Two rings may be interconnected through a common node, such as node 105, also known as an internal interconnect. Two rings may also be connected through an external interconnect between nodes on each ring.
Occasionally, services must be provisioned on the network. During the provisioning process, a path between two end points, through nodes, rings and interconnects, must be determined. The selection of the path is based upon the available resources necessary for the service and the service parameters. One important resource is bandwidth. As the multiplexing of different services on an optical network becomes more popular, the effectiveness of bandwidth management in service provisioning becomes more important. If the service provisioning is inefficient, then bandwidth can be wasted, costing money.
An example of inefficient provisioning is not routing each service over the shortest available path between its endpoints. This causes fewer services to fit in a given network than could be possible.
As another example, some service have higher priority than others. In provisioning high priority services on conventional optical networks, bandwidth is guaranteed by using dedicated connections, even though the full bandwidth of the dedicated connection is not always in use. This utilizes available bandwidth inefficiently.
Accordingly, there exists a need for an improved method and system for selecting ring paths in service provisioning on optical networks. The method and system should minimize the resources utilized by a service. The present invention addresses such a need.